In trading on Thursday, shares of the iShares 2017 S&P AMT-Free Municipal Series ETF ( MUAF) entered into oversold territory, changing hands as low as $54.76 per share. We define oversold territory using the Relative Strength Index, or RSI, which is a technical analysis indicator used to measure momentum on a scale of zero to 100. A stock is considered to be oversold if the RSI reading falls below 30.In the case of iShares 2017 S&P AMT-Free Municipal Series, the RSI reading has hit 28.5 — by comparison, the RSI reading for the S&P 500 is currently 47.0. A bullish investor could look at MUAF's 28.5 reading as a sign that the recent heavy selling is in the process of exhausting itself, and begin to look for entry point opportunities on the buy side. Looking at a chart of one year performance (below), MUAF's low point in its 52 week range is $54.70 per share, with $56.40 as the 52 week high point — that compares with a last trade of $54.80. iShares 2017 S&P AMT-Free Municipal Series shares are currently trading off about 0.3% on the day.